This invention relates generally to a cleaning apparatus, and more particularly concerns adjusting the blade load on a detoning roll.
The scraper blade in present detoning roll cleaners supply a uniform load along the length of the detoning roll. The force from the blade scrapes the toner off the detoning roll. The wear of both the detoning roll and scraper blade are directly proportional to the load supplied by the scraper blade (i.e. the higher the load, the faster the wear rate on the detoning roll). The amount of toner applied between the roll and the scraper blade is inversely proportional to the wear rate. The more toner applied to the detoning roll, the better the lubrication between the detoning roll and the scraper blade resulting in a slower wear rate. However, the amount of toner at the ends of the detoning roll is less than the amount at the center because most images on the photoreceptor have higher densities in the middle than on the ends. This results in a higher frictional force on the ends of the detoning roll than in the center. Hence, the detoning roll has a faster wear rate on the ends causing the detoning roll ends to wear out before the middle. For detoning rolls with an anodized coating, the detoning roll wore until the anodized coating was thin enough that pin holes occurred on the surface of the roll. Thus, decreasing the efficiency and overall life of the roll.
A present solution, to uneven wear of the detoning roll, has been to compromise both performance and life of the detoning roll by slowing down the cleaner, to reduce the overall wear rate on the detoning roll and shortening the scraper blade to reduce the end wear on the detoning rolls.
The following disclosures may be relevant to various aspects of the present invention and may be briefly summarized as follows:
U.S. Pat. No. 5,243,385 to Thayer discloses a center portion of a backing photoreceptor support roll is proportionately bowed outward toward the cleaning blade to compensate for nonuniform belt tension under the blade cleaner due to the deflection of the backing support roll. This results in a uniform cleaning blade load and enhanced cleaning across a compliant belt photoreceptor having non-uniform belt tension, that is inexpensive and easy to manufacture and implement.
U.S. Pat. No. 5,209,997 to Fromm et al. discloses a three roll fuser including a fuser roll, pressure roll and a backup roll. The backup roll is crowned and is supported in pressure engagement with the fuser roll to form a first nip while the fuser roll is also supported in contact with the pressure roll. The pressure engagement of the crowned roll with the fuser roll eliminates nonuniform nip loading in wide fusers as well as providing uniform velocity through the fuser roll/pressure roll nip.